Add Array `findIndex` support

What does this MR do?

Adds support polyfill for Array.prototype.findIndex in ES6.

Why was this MR needed?

We have several places in code where we end up using forEach on array to find index of particular object, while ideal method to do so is findIndex.

Does this MR meet the acceptance criteria?

• [ ] Changelog entry added, if necessary
• [ ] Documentation created/updated
• [ ] API support added
• Tests
  • [ ] Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #33315 (closed)